1. Field of the Invention
The present invention relates to a dispenser package for flowable products and the like and, more specifically, to a new configuration and structure of a stress concentrator for a dispenser package which contains and dispenses a quantity of flowable product normally called for in a single use.
2. Description of the Prior Art
Various attempts have heretofore been made to provide a dispenser package into which a flowable product may be packaged in the quantity normally required for a single use, and from which such flowable material may be dispensed.
The Redmond U.S. Pat. No. 3,986,640, (hereinafter the 640 patent) discloses a dispenser package which represents a marked improvement over prior package structures in that it accomplishes efficient dispensing of a predetermined quantity of the contents with a one handed motion and without presenting the opening difficulties previously associated with opening by removal of a cover or tearing of an envelope or pouch.
The Redmond et al U.S. Pat. No. 4,493,574 discloses a dispenser package similar to that of the Redmond 640 patent but includes the use of at least one stress concentrating protrusion member displacing at least a portion of the fault line or fault pattern out of the plane of the relatively stiff member. The preferred embodiment of the protrusion member there disclosed has a substantially pyramidal shape which displaces the fault across the apex thereof and is substantially symmetrical with respect to both the fault line.
While the aforesaid structures of the 574 patent represent a marked improvement over both the 640 patented structure and all previously known dispenser package structures, it has been found that the use of a generally symmetrically positioned stress concentrating protrusion member may suffer certain drawbacks under certain conditions.
Thus, it has been found that the relative (i) height of the symmetrical protrusion member, (ii) thickness of the sheet material, (iii) desired opening size and (iv) included angle between the symmetrical sides of the stress concentrator along a line normal to the fault line are interdependent--i.e., as the desired opening size becomes larger, the height of the protrusion member necessarily becomes greater and the walls therefore become thinner and the aforesaid included angle is and to an axis or line normal to the fault line. reduced. Consequently, as the desired opening size becomes larger, the thickness of the sheet material must be increased so that the walls of the protrusion member retain sufficient thickness to retain barrier qualities along the fault line, particularly at its peak, as well as to retain enough strength so as not to collapse, but rupture, upon bending of the relatively stiff flat sheet into a "V" shape in order to dispense the contents of the package.
It is also not always possible to simply decrease the height of the protrusion member as the width of the opening becomes greater since it also has been found that, if too shallow for a given width, the protrusion member will then flatten and lose its stress concentrating ability, resulting in an inability to rupture to open the package upon bending of the package into the "V" shape.
A further drawback of the required increase in height of the protrusion member as the opening size increases is that it may result in a lessened ability to compactly store and ship the packages or make such storage and shipment more difficult.
Finally, there are certain products which are mixed or otherwise combined at the time of use but which must be kept isolated prior to use, such as epoxy mixes and dental products, and other products which it is desirable to store separately and mix or combine at the time of use, such as salad dressings (e.g., oil and vinegar), peanut butter and jelly, etc. For these products, it would be desirable to connect two or more isolated dispenser package structures as disclosed in the 574 patent in side-by-side relationship with a protrusion member located above each pouch or chamber. However, it has been found that in such a package configuration the generally symmetrical protrusion member disclosed in the 574 patent suffers the further drawback that the resultant openings may be spread farther apart than may be desirable for conveniently combining the products upon rupture of the protrusion members.
3. Objects of the Invention
It is therefore an object of this invention to provide a new and improved dispenser package for flowable products.
Another object of this invention is to provide a new and improved dispenser package for flowable products which overcomes the aforesaid drawbacks of the generally symmetrical protrusion members disclosed in the aforesaid 574 patent.
Another object of this invention is to provide a new and improved stress concentrating means for rupturing tough materials or combinations thereof in a dispenser package upon their being bent into a "V" shape and which permits use of a thinner, and therefore more econimcal, relatively stiff flat sheet material.
Another object of this invention is to provide a new and improved dispenser package for flowable products in which the stress concentrating protrusion member is asymmetrical about a line or axis normal to the fault line or fault pattern.
A further object of this invention is to provide a new and improved dispenser package which may be combined into a duplex or multiplex package for flowable products which require isolation prior to use.
A further object of this invention is to provide a new and improved dispenser package which simultaneously dispenses two or more discrete flowable products which are isolated from each other prior to being dispensed.
A still further object of this invention is to provide a new and improved duplex or multiplex dispenser package which improves prior dispenser packages in the containment of at least two discrete flowable substances which are isolated from each other until the time of application, by providing closely spaced asymmetric protrusion members which displace the fault line or fault pattern out of the plane of the relatively stiff sheet member and which rupture the fault upon bending to produce at least two separate but closely spaced openings through which the aforesaid flowable substances are separately and simultaneously dispensed.
A still further object of this invention is to provide a new and improved dispenser package which improves prior dispenser packages for the containment of flowable products by forming the stress concentrating protrusion member in the shape of a substantially semi- or split pyramidal configuration which displaces the fault line or fault pattern out of the plane of the relatively stiff sheet member and is positioned so as to be substantially symmetrical to the fault but asymmetrical to a line or axis normal to the fault.
A still further object of this invention is to provide a new and improved duplex or multiplex dispenser package which accurately dispenses unequal quantities of two or more flowable products.
Objects and advantages of the invention are set forth in part herein and in part will be obvious therefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.
The invention consists of the novel parts, constructions, arrangements, combinations, steps and improvements herein shown and described.